The Influence of Impurity Scattering in Highly Doped SOI-MOSFETs

The relationship between the most commonly used empirical and physical mobility models is investigated. The parameters of the empirical model are given as a function of those of the physical model. Based on these relations, it will be shown that the three empirical mobility parameters μ
₀
, θ
₁
and θ
₂
are influenced by impurity scattering which increases with the doping concentration. This mechanism can be dominant in the linear mobility reduction factor θ
₁
which may become negative. Experimental results of highly doped SOI-MOSFETs demonstrate that impurity scattering cannot be neglected any longer at ambient and higher temperatures.